ON A MAP OF NORTH AMERICA, the Baja Peninsula is that finger of land, more like a pinkie, that juts out from Mexico's west coast. Its length is the distance between Chicago and New York, and in places it's less than 50 miles wide. Thanks to its narrowness, and its remote ruggedness, Baja has only one major road, the Transpeninsular Highway, or Mex 1, which runs for 1,000 miles, zigzagging back and forth as if caught in a custody battle between the Pacific Ocean and the Sea of Cortez.

Our itinerary was simple: In the mornings, Danny would add up how many hours of driving were ahead of us, then he'd divide that number by how many days we had left. Our average goal came out to 150 miles a day, but the actual distances we covered were heavily influenced by roadside distractions and the scant distribution of towns and their accompanying services, such as cold beer, tacos, gas, and lodging: Ensenada to San Quintín, 119 miles; El Rosario to Cataviña, 76 miles; Guerrero Negro to San Ignacio, 88 miles; Ciudad Constitución to La Paz, 134 miles.

We fled Tijuana immediately, partly because it was raining and partly because of rumors of a crime wave. Throughout 2006 and 2007, Baja was the site of a number of kidnappings and robberies committed against American tourists by masked, gun-toting gangs dressed in commando outfits. The attacks prompted a U.S. State Department travel alert in October 2007 and garnered enough media attention to have a significant impact on tourism. The number of visitors to the entire Baja Peninsula plummeted in 2007, even though the crimes have been largely relegated to the extreme northern regions, around Tijuana. I had mixed emotions about this development: There were fewer people to distract the banditos away from yours truly, but there were bound to be a lot more deserted beaches.

But first we had to outrun a couple hundred miles' worth of drizzle and overcast skies. We finally got ahead of the weather while Mex 1 was taking a long inland sojourn to the interior's Desierto Central, where we found a room at the Desert Inn in Cataviña, a small, dusty village with a scattering of houses and an intermittently open gas station. When the sun rose, we couldn't believe what was lying just outside the window: The land was peppered with many-armed, 30- and 40-foot-tall cardon cacti, the largest cactus species in the world, weighing up to 20 tons.

We headed south in the rental, entering the heart of the Central Desert. I was just getting into my driving groove when I realized that Matt needed an attitude adjustment. That's what my dad called it when he pulled the car over on family road trips and hauled me and my brothers outside for a quick curbside spanking. I resented it at the time, but in Baja I could see where he was coming from. First Matt got fussy and adjusted his legs so that his bare feet were on my armrest. I was just about to comment on his toenails, which are as thick as window glass (he claims that it's from eating too much game meat), when he let out a few of his signature moaning complaints: "Boring... boring!"

Matt is six foot two and over 200 pounds, which means he outclasses my ability to give him a proper "adjustment." The only thing we could do was plead. Everyone cried out in unison, "Matt, please…" and that shut him up for a minute. I knew the problem: Matt sometimes needs to walk across land before he believes in it, so I found a place to pull over.

Out past the "trash zone," the desert swallowed up the very idea of civilization. The landscape seemed designed for the purpose of inflicting human pain. The ground was hard enough to crack open your skull. The plant life looked as though it had lived through an explosion in a needle factory; everything had spikes and thorns growing out of it, some long enough to pass into your arm and come out the other side. We wandered as though in a drugged trance, silently enjoying the rawness of being somewhere that could dry you out and pick your bones clean in a matter of hours. After a while, Matt announced that he was ready to get back in the van.